package com.module2hw;

import java.lang.reflect.Array;
import java.text.DecimalFormat;
import java.util.Arrays;
import java.util.Random;

public class Main {

    private static Random rand = new Random();
    private static int n1 = 100000, n2 = 120000;

    public static void main(String[] args) {
        //how the heck we are comparing c++ with java using different random data sets???

        Long[] arr1 = generateNumbers(n1);
        Long[] arr2 = generateNumbers(n2);

        Long startTime = System.nanoTime();

        Arrays.sort(arr1);
        Arrays.sort(arr2);

        Long[] arr3 = mergeSortedArrays(arr1,arr2);

        Long time = System.nanoTime() - startTime;

        DecimalFormat formatter = new DecimalFormat("#0.000000000");
        System.out.println("Elapsed time without arrays generation: " + formatter.format(time/1e9) + " sec.");
    }

    private static Long[] generateNumbers(int n) {
        Long[] array = new Long[n];
        for(int i = 0; i < array.length; i++) {
            array[i] = rand.nextLong();
        }
        return array;
    }

    private static Long[] mergeSortedArrays(Long[] arr1, Long[] arr2) {
        int i = 0, j = 0, k = 0;
        Long[] result = new Long[arr1.length + arr2.length];

        //part of merge sort algorithm
        while(i < arr1.length && j < arr2.length) {
            result[k++] = arr1[i] <= arr2[j] ? arr1[i++] : arr2[j++];
        }

        while(i < arr1.length) result[k++] = arr1[i++];
        while(j < arr2.length) result[k++] = arr2[j++];
        //-=-=-=-=-=-

        return result;
    }
}